Sains Malaysiana 42(2)(2013): 239–246

Effect of Al and N Doping on Structural and Optical Properties of Sol-Gel Derived ZnO Thin Films

(Kesan Pengedopan Al dan N Terhadap Struktur dan Sifat Optik Filem Nipis ZnO yang Disediakan Melalui Kaedah Sol-Gel)

Chatpong Bangbai^1*, Krisana Chongsri², Wisanu Pecharapa^3,4 & Wicharn Techitdheera¹

¹School of Applied Physics, King Mongkut’s Institute of Technology Ladkrabang

Ladkrabang, Bangkok, 10520, Thailand

²Department of Applied Physics, Faculty of Science and Technology

Rajabhat Rajanagarindra University, Chachoengsao, 24000, Thailand

³College of Nanotechnology, King Mongkut’s Institute of Technology Ladkrabang

Ladkrabang, Bangkok 10520, Thailand

⁴ThEP Center, CHE, 328 Siayuthtaya Rd. Bangkok, 10400, Thailand

Received: 7 January 2012/Accepted: 21 May 2012

ABSTRACT

In this work, the preparation of ZnO, N-doped ZnO (NZO), Al-doped ZnO (AZO) and Al, N-doped ZnO (ANZO) thin films by the sol-gel spin-coating method is reported. The structural properties and surface morphologies of films were characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optical properties of the films were interpreted from their transmission spectra using UV-VIS spectrophotometer. The XRD and SEM results disclosed that the crystallization quality and grain size of as-prepared films were highly influenced by N and Al doping. UV-VIS spectrophotometer results indicated that Al and N additives could significantly enhance the optical transparency and induce the blue-shift in optical bandgap of ZnO films.

Keywords: Al doping; N doping; sol-gel; ZnO thin films

ABSTRAK

Di dalam kajian ini, penyediaan saput tipis ZnO, N-terdop ZnO (NZO), Al-terdop ZnO (AZO) dan Al, N-terdop ZnO (ANZO) menggunakan kaedah salutan-putaran sol-gel dilaporkan. Sifat-sifat struktur dan morfologi permukaan filem dicirikan menggunakan pembelauan sinar-X (XRD) dan mikroskop imbasan elektron pancaran medan (FE-SEM). Sifat optik filem tersebut diperoleh daripada spektrum transmisi dengan menggunakan spektrofotometer UV-VIS. Keputusan XRD dan SEM membuktikan bahawa kualiti penghabluran dan saiz butiran filem yang disediakan sangat dipengaruhi oleh pendopan N dan Al. Keputusan UV-VIS spektrofotometer menunjukkan bahawa bahan tambahan Al dan N dapat meningkatkan kelutsinaran optik dan menpengaruhi anjakan biru antara jurang jalur optik filem ZnO secara signifikan.

 Kata kunci:  Pengedopan Al, pengedopan N; :saput tipis ZnO; sol-gel

REFERENCES

Ayouchi, R., Leinen, D., Martin, F., Gabas, M., Dalchiele, E. & Ramos-Barrado, J.R. 2003. Preparation and characterization of transparent ZnO thin films obtained by spray pyrolysis. Thin Solid Films 426: 68-77.

Bouzidi, A., Benramdane, N., Medles, M., Khadraoui, M., Bresson, S., Mathieu, C., Desfeux, R. & Marssi, M. El. 2010. Synthesis of LiVO3 thin films by spray pyrolysis technique. Journal of Alloys and Compounds 503(2): 445-448.

Chichibu, S.F., Ohmori, T., Shibata, N., Koyama, T. & Onuma, T. 2005. Fabrication of p-CuGaS2/n-ZnO: Al heterojunction light-emitting diode grown by metalorganic vapor phase epitaxy and helicon-wave-excited-plasma sputtering methods. Journal of Physics and Chemistry of Solids 66: 1868-1871.

Cracium, V., Elders, J., Gardeniers, J.G.E. & Boyd, I.W. 1994. Characteristics of high quality ZnO thin films deposited by pulsed laser deposition. Applied Physics Letters 65(23): 2963-2965.

Kashiwaba, Y., Sugawara, K., Haga, K., Watanabe, H., Zhang, B.P. & Segawa, Y. 2002. Characteristics of c-axis oriented large grain ZnO films prepared by low pressure MO-CVD method. Thin Solid Films 411: 87-90.

Kim, K.H., Park, K.C. & Ma, D.Y. 1997. Structural, electrical and optical properties of aluminum doped zinc oxide films prepared by radio frequency magnetron sputtering. Journal of Applied Physics 81: 7764-7772.

Kim, Y.S. & Tai, W.P. 2007. Electrical and optical properties of Al-doped ZnO thin films by sol-gel process. Applied Surface Science 253: 4911-4916.

Kuo, S.Y., Chen, W.C., Lai, F.I., Cheng, C.P., Kuo, H.C., Wang, S.C. & Hsieh, W.F. 2006. Effects of doping concentration and annealing temperature on properties of highly-oriented Al-doped ZnO films. Journal of Crystal Growth 287(1): 78-84.

Li, C., Meng, F.Y., Zhang, S. & Wang, J.Q. 2010. Effects of Mg content and B doping on structural, electrical and optical properties of Zn₁-xMgxO thin films prepared by MOCVD. Journal of Crystal Growth 312: 1929-1934.

Liu, W.W., Yao, B., Li, Y.F., Li, B.H., Zhang, Z.Z., Shan, C.X., Zhang, J.Y., Shen, D.Z. & Fan, X.W. 2010. P-Type MgZnO thin films grown using N delta-doping by plasma-assisted molecular beam epitaxy. Journal of Alloys and Compounds 504: 484-487.

Marotti, R.E., Giorgi, P., Machado, G. & Dalchiele, E.A. 2006. Crystallite size dependence of band gap energy for electrodeposited ZnO grown at different temperatures. Solar Energy Materials and Solar Cells 90: 2356-2361.

Nunes, P., Fortunato, E., Tonello, P., Fernandes, F.B., Vilarinho, P. & Martins, R. 2002. Effect of different dopant elements on the properties of ZnO thin films. Vacuum 64: 281-285.

Sui, Y.R., Yao, B., Yang, J.H., Gao, L.L., Yang, T., Deng, R., Ding, M., Zhao, T.T., Huang, X.M., Pan, H.L. & Shen, D.Z. 2010. Post-annealing influence on electrical properties and photoluminescence of B–N codoping ZnO thin films. Journal of Luminescence 130: 1101-1105.

Wang, J., Meng, L., Qi, Y., Li, M., Shi, G. & Liu, M. 2009. The Al-doping contents dependence of the crystal growth and energy band structure in Al:ZnO thin films. Journal of Crystal Growth 311: 2305-2308.

Wang, M., Warg, J., Chen, W., Cui, Y. & Wang, L. 2006. Effect of preheating and annealing temperatures on quality 

characteristics of ZnO thin film prepared by sol–gel method. Materials Chemistry and Physics 97: 219-225.

Wang, T., Liu, Y., Fang, Q., Wu, M., Sun, X. & Lu, F. 2011. Low temperature synthesis wide optical band gap Al and (Al, Na) co-doped ZnO thin films. Applied Surface Science 257: 2341-2345.

Xue, S.W., Zu, X.T., Zheng, W.G., Chen, M.Y. & Xiang, X. 2006. Effects of annealing and dopant concentration on the optical characteristics of ZnO:Al thin films by sol–gel technique. Physica B 382: 201-204.

Zeng, Y.J., Ye, Z.Z., Xu, W.Z., Liu, B., Che, Y., Zhu, L.P. & Zhao, B.H. 2007. Study on the Hall-effect and photoluminescence of N-doped p-type ZnO thin films. Materials Letters 61: 41-44.

Zhang, C. 2010. High-quality oriented ZnO films grown by sol-gel process assisted with ZnO seed layer. Journal of Physics and Chemistry of Solids 71: 364-369.

Zhang, Z., Zhang, Y., Duan, L., Lin, B. & Fu, Z. 2006. Deep ultraviolet emission of ZnO films prepared by RF-magnetron sputtering at changing substrate temperature. Journal of Crystal Growth 290: 341-344.

Zhao, Y., Peng, X., Li, Z., Zhou, M., Liang, X., Wang, J., Min, J., Wang, L. & Shi, W. 2012. The photoluminescence characterization of the N-doped ZnO films produced by wet chemical deposition. Applied Physics A 107: 959-963.

Zhou, H., Fang, G.J., Liu, N. & Zhao, X.Z. 2011. Effects of thermal annealing on the performance of Al/ZnO nanorods/Pt structure ultraviolet photodetector. Materials Science and Engineering B 176: 740-744.

Zi-qiang, X., Hong, D., Yan, L. & Hang. C. 2006. Al-doping effects on structure, electrical and optical properties of c-axis-orientated ZnO: Al thin films. Materials Science in Semiconductor Processing 9: 132-135.

Znaidia, L., Soler Illia, G.J.A.A., Benyahia, S., Sanchez, C. & Kanaev, A.V. 2003. Oriented ZnO thin films synthesized by sol-gel process for laser application. Thin Solid Films 428: 257-262.

Zou, C.W., Chen, R.Q. & Gao, W. 2009. The microstructures and the electrical and optical properties of ZnO: N films prepared by thermal oxidation of Zn3N2 precursor. Solid State Communications 149: 2085-2089.

*Corresponding author; email: chatpong_b@windowslive.com